| Ni | Symbol for nickel. (05 Mar 2000) |
|---|---|
| niacin | <biochemistry> Member of the water soluble B vitamin group, used in the production of fatty acids, steroids and cholesterol, deficiency is known as pellagra. Has cholesterol-lowering and vasodilating properties. (27 Sep 1997) |
| niacin deficiency | <biochemistry> A niacin deficiency disease (pellagra) caused by improper diet and characterised by skin lesions, gastrointestinal disturbances and nervousness. Depression, dermatitis, dementia and diarrhoea are common symptoms. (27 Sep 1997) |
| niacin test | A test of the ability of mycobacteria to elaborate niacin; used to distinguish different strains. (05 Mar 2000) |
| niacinamide | <biochemistry> Member of the water soluble B vitamin group, used in the production of fatty acids, steroids and cholesterol, deficiency is known as pellagra. Has cholesterol-lowering and vasodilating properties. (27 Sep 1997) |
| niagara period | <geology> A subdivision or the American Upper Silurian system, embracing the Medina, Clinton, and Niagara epoch. The rocks of the Niagara epoch, mostly limestones, are extensively distributed, and at Niagara Falls consist of about eighty feet of shale supporting a greater thickness of limestone, which is gradually undermined by the removal of the shale. See Chart of Geology. Source: Websters Dictionary (01 Mar 1998) |
| nialamide | <chemical> An mao inhibitor that is used as an antidepressive agent. Pharmacological action: antidepressive agents, monoamine oxidase inhibitors. Chemical name: 4-Pyridinecarboxylic acid, 2-(3-oxo-3-((phenylmethyl)amino)propyl)hydrazide (12 Dec 1998) |
| niasome | <pharmacology> Multilamellate liposomes made from nonionic lipids and used for drug delivery. Origin: Gr. Soma = body (18 Nov 1997) |
| nib | 1. A small and pointed thing or part; a point; a prong. "The little nib or fructifying principle." 2. <zoology> The bill or beak of a bird; the neb. 3. The points of a pen; also, the pointed part of a pen; a short pen adapted for insertion in a holder. 4. One of the handles which project from a scythe snath; also, the shaft of a wagon. Origin: A variabt of neb. Source: Websters Dictionary (01 Mar 1998) |
| nibble | To bite upon something gently or cautiously; to eat a little of a thing, as by taking small bits cautiously; as, fishes nibble at the bait. "Instead of returning a full answer to my book, he manifestly falls a-nibbling at one single passage." (Tillotson) Source: Websters Dictionary (01 Mar 1998) |
| nicagua | <zoology> The laughing falcon. See laughing. Source: Websters Dictionary (01 Mar 1998) |
| nicaragua wood | 1. The wood of the oriental Caesalpinia Sapan; so called before the discovery of America. 2. A very heavy wood of a reddish colour, imported from Brazil and other tropical countries, for cabinet-work, and for dyeing. The best is the heartwood of Caesalpinia echinata, a leguminous tree; but other trees also yield it. An interior sort comes from Jamaica, the timber of C. Braziliensis and C. Crista. This is often distinguished as Braziletto, but the better kind is also frequently so named. Origin: OE. Brasil, LL. Brasile (cf. Pg. & Sp. Brasil, Pr. Bresil, Pr. Bresil); perh. From Sp. Or Pg. Brasa a live coal (cf. Braze, Brasier); or Ar. Vars plant for dyeing red or yellow. This name was given to the wood from its colour; and it is said that King Emanuel, of Portugal, gave the name Brazil to the country in South America on account of its producing this wood. Source: Websters Dictionary (01 Mar 1998) |
| nicarbazin | <chemical> An equimolar complex of 4,4'-dinitrocarbanilide and 2-hydroxy-4,6-dimethylpyrimidine. A coccidiostat for poultry. Pharmacological action: coccidiostats. Chemical name: Urea, N,N'-bis(4-nitrophenyl)-, compd. With 4,6-dimethyl-2(1H)-pyrimidinone (1:1) (12 Dec 1998) |
| nicardipine | <chemical> 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl) methyl 2-(methyl(phenylmethyl)amino)-3,5-pyridinecarboxylic acid ethyl ester. A potent calcium channel blockader with marked vasodilator action. It has antihypertensive properties and is effective in the treatment of angina and coronary spasms without showing cardiodepressant effects. It has also been used in the treatment of asthma and enhances the action of specific antineoplastic agent. Pharmacological action: anti-asthmatic agents, antihypertensive agents, calcium channel blockers, vasodilator agents. Chemical name: 3,5-Pyridinedicarboxylic acid, 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-, methyl 2-(methyl(phenylmethyl)amino)ethyl ester (12 Dec 1998) |
| niccolite | <chemical> A mineral of a copper-red colour and metallic luster; an arsenide of nickel. Synonym: coppernickel, kupfernickel. Origin: from NL. Niccolum nickel. Source: Websters Dictionary (01 Mar 1998) |